#include<iostream>
using namespace std;
void TestPushBack()
{
    string s;
    size_t sz = s.capacity();
    cout << sz << endl;
    cout << "making s grow:\n";
    for (int i = 0; i < 100; ++i)
    {
        s.push_back('c');
        if (sz != s.capacity())
        {
            sz = s.capacity();
            cout << "capacity changed: " << sz << '\n';
        }
    }
}
int main()
{
	TestPushBack();
	return 0;
}
